Electron discharge device and cantilever support means therefor



May 31, 1966 A. VAN DER JAGT 3,254,259

ELECTRON DISCHARGE DEVICE AND CANTILEVER MEANS THEREFOR Filed Nov. 16, 1962 2 Sheets-Sheet 1 Fig.l.

INVENTOR Anton van der Jcg'r pin 12W ATTORNEY May 31, 1966 A. VAN DER JAGT 4 3,254,259

ELECTRON DISCHARGE DEVICE AND GANTILEVER MEANS THEREFOR Filed Nov. 16, 1962 2 Sheets-Sheet 2 larly those of the receiving tube type.

United States Patent 3,254,259 ELECTRON DISCHARGE DEVICE AND CAN. LEVER SUPPORT MEANS THEREFOR Anton van der Jagt, Wheeler Township, Steuben County,

N.Y., assignor to Westinghouse Electric Corporation,

'Pittsburgh, Pa., a corporation of Pennsylvania Filed Nov. 16, 1962,'Ser. No. 238,230 3 Claims. (Cl. 313-260) The present invention relates to electron discharge devices and, more particularly, to an improved electrode cage assembly and means for supporting this assembly.

It is known in the prior art'that electrodes of the cage assembly may be supported in a cantilever fashion; that is, supported at only one thereof. However, prior art devices of this nature have generally suffered from several disadvantages. One of the major disadvantages stems from the fact that these devices are not readily manufactured on regular, existing standard equipment utilized in the manufacture of other discharge devices. Also, the pin connections of these devices are difierent from those of standard tubes. Thus, with the use of these prior art devices, it is not possible to use standard tube sockets and, therefore, these tubes may not replace standard tubes in existing apparatus.

It is, therefore, an object of this invention to provide an improved electron discharge device.

A further object is to provide an electron tube including an electrode cage assembly of improved cantilever design.

Another object is to provide an improved electrode cage assembly of cantilever design which utilizes standard tube envelopes and connections.

A still further object is to provide an electron discharge device of improved performance which may be readily V r and economically manufactured.

Stated briefly, the present invention describes a design or construction for electron discharge-devices, particu- Tubes made in accordance with the present invention are of cantilever design; that is, the electrodes of the cage assembly are supported at only one end thereof. In the preferred embodiment, the various cage asesmbly electrodes are pre-assembled with their support structures. These pre-assembled electrodes are then secured to an insulating disc which in turn, is supported by stem leads extending through one end of the tube. The various elements are secured to the disc by providing within the disc a plurality of apertures and, by providing on the electrodes, or on their associated support structures, tab portions which extend through the apertures and which are bent to secure the electrodes to the insulating disc.

Further objects and advantages of the invention will become apparent as the following description proceeds and features of novelty which characterize the invention will be pointed out in particularlity in the claims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which:

FIGURE 1 is a view, partially broken away and partially in section, of an electron discharge device showing the present invention in its preferred form; and

FIG. 2 is an exploded view showing the cage assembly of the device of FIG. 1.

With reference now to FIGS. 1 and 2, there is shown a discharge device including an envelope which is closed at one end and which is provided with a tipped-off exhaust tube 14. The other end of the envelope 10 is provided with a button stem header 12 in a manner well known in the art. A plurality of electrically conductive pin members 16 through 20 inclusive are provided which extend through the stem header 12. An electrode cage assem- 3,254,259 Patented May 31, 1966 bly indicated generally at is disposed within the envelope 10.

As shown, the preferred embodiment of the invention includes a single supporting member or disc 26 of electrically insulating material. This disc may be in the form of the customary mica spacer found in receiving tubes. The support member 26 is maintained in position within the envelope 10 by being secured to preferably three or more of the pin leads 16 through 20. In the particular embodiment shown, the support member 26 is affixed to pins 16, 20 and a third pin which has not been shown. The support member 26 is also provided with a plurality of apertures extending therethrough in order to facilitate the securing of the various elements of the cage assembly 30 to the member 26. i

The cage assembly 30 includes a cathode 32, a grid member 42 and an anode 48. I The cathode 32 comprises an inner tubular member 33 and an outer tubular member 35. The tubular members 33 and are spaced from each other and are, preferably, in the form of concentric cylindrical tubes; although, it is obvious that other configurations than circular may be used. The inner tube 33 is preferably of 'a low heat conducting material such as Inconel; an International Nickel Co. trademark for a high nickel-chromium alloy containing about 79.5% nickel, 13% chromium, 6.5% iron, and lesser amounts of manganese, silicon, carbon and copper. The tubular members 33 and 35 are held in a spaced relationship and the outer member is supported by the inner member through the utilization of a washer or apertured disc 34 which is positioned between the two members 33 and 35 at their upper edge. The disc 34 is retained in position by welding it to the inner and outer members 33 and 35 along their contacting surfaces to form a unitary structure. It is seen that the washer 34 not only spaces the two tubular members 33 and 35, but also acts as a means for supporting the outer member 35from the inner tubular member 33. The washer 34 also serves to close oil the space between the two tubular members 33 and 35 and thus prevent the loss of heat therefrom through radiation. The washer 34 is preferably made of a good heat conducting material, for example, nickel.

A heater 37 is positioned within the space between the two tubular members 33 and 35 to provide for the indirect heating of the cathode. The heater 37 is shown to be of the coil variety and includes an insulated resistance wire. Any suitable electron emissive coating 36 such as are Well known in the art is placed on the outside surface of the outer tubular member 35 to provide for electron emission upon the heating of the cathode.

The cathode is also provided with a suitable shield or flange 38 positioned near the bottom end of the tubular member 33. The shield 38 may be formed integrally with the member 33 or may be a separate washer or apertured disc which is affxed to the inner tube 33 by suitable means such as brazing. The cathode 32 is secured to the support member 26 through the utilization of a rivet member 40 having a head portion 39 and a body portion 41. The head portion 39 of the rivet is of sufi'icient diameter to extend beyond the inner tubular portion 33. The body portion 41 extends through an aperture in the mica. The body portion 41 is of sufiicient diameter to provide a compression or force fit within the inner tubular member 33. Thus, it is seen that the cathode 32 is held in a cantilever fashion from the support member 26 by forcing the body portion 41 of the rivet into the inner tubular member 33 with the head 39 of the rivet bearing against the lower surface of the support member 26. A more complete description of the cathode 32, and alternate forms thereof, may be found in applicants copending application, Serial No. 238,229, entitled Electron Discharge Device, now Patent No. 3,195,003 assigned to the assignee of the 0 present invention, and filed concurrently herewith (assignees case number 33,309). It is also obvious that other forms of cathodes other than the double walled structure shown may be utilized in the present invention.

The grid 42 is disposed around the cathode 32 and is preferably coaxial therewith. The grid 42 is secured at its lower edge to a support member 43 which has a flange 44 extending radially in a direction transverse to the axis of the grid 42. The flange 44 rests on the top side of the support member 26. The member 43 is also provided with one or more projecting tabs 45 which extend through suitable apertures in the support member 26 and are bent to provide that a portion of the tab 45 is in contact with the lower surface of the support member 26. In this way, the grid 42 is also supported in a cantilever fashion from the support member 26. The grid member 42 is preferably one which does not utilize heavy side rods.

An anode 48 which is also preferably of circular configuration constitutes the outer element of the electrode cage assembly. The anode may be of a suitable material such as nickel and includes a vertically extending portion 49 which is substantially the same length as the emissive coating 36 on the cathode 32. The anode 48 is provided with a portion 50 which extends from the bottom of the vertical section 49 in a direction transverse thereto. The portion 50 is provided with a plurality of tab portions 51 which extend vertically downward from the outer edge of the shield portion 5% through the support member 26. Each tab 51 is provided with a reduced cross sectional area portion at the point at which it passes through the support member 26. Thus, the non-reduced portion of the tab 51 rests on the top side of the mica and the portion extending through the mica may be bent to hold the anode in position.

If it is desired to place more than one grid in the device, it is obvious that the horizontally extending portion 5% of the anode 48 may be reduced in its horizontal dimension to provide additional spacing between the cathode 32 and the anode 43.

It is thus seen that there has been described an improved design for an electron discharge device cage assembly. The assembly described is of cantilever construction and is one which may be readily manufactured on existing apparatus. type of base which is standard to receiving type tubes. Hence, the device of the present construction may be utilized in sockets of existing equipment, thus alleviating any necessity of special sockets and connectors.

While there have been shown and described what are at present considered to be the preferred embodiments of the invention, modifications thereto will readily occur to those skilled in the art.

For example, .in certain circumstances it may be desirable to utilize more than one insulating disc in the device to act as spacers and/or insulators between the various elements of the cage assembly. An example of this would be to place a second disc, having a center aperture large enough to fit over the grid, on the upper surface of the flange 44. This second disc would have Additionally, the device employs a v 4 apertures through which the tabs 51 on the anode would fit.

It is not desired, therefore, that the invention be limited to the specific arrangment shown and described, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

I claim as my invention:

1. An electron discharge device comprising an evacuated envelope, a plurality of unitary leads disposed in a regular array, each of said leads extending through and being supported by said envelope, an electrically insulating disc disposed within said envelope and a plurality of electrodes having a first and second end portion, said electrodes being supported in a spaced relationship upon said disc, said first end portion being supported on said disc and said second end portion remaining unsupported, at least one of said leads secured to said disc and electrically connected to one of said plurality of electrodes.

2. An electron discharge device comprising an envelope having a plurality of unitary, rigid leads, said leads extending through and being supported by said envelope in a circular array, a thin disc of electrically insulating material disposed within said envelope and supported by said leads, a cage assembly including a plurality of electrodes, said electrodes having first and second end portions, said first end portion of said electrodes being secured to said thin disc, said second end portion remaining unsupported, said disc supporting said electrodes and maintaining said electrodes in a spaced relationship, at least one of said leads being secured to said disc for the support thereof and electrically attached to one of said electrodes to provide an electrical connection to a point exterior of said envelope.

3. An electron discharge device comprising an evacuated envelope, a first and second rigid lead extending through and secured to said envelope, a cage assembly including a plurality of spaced electrodes disposed within said envelope, means within said envelope for supporting said electrodes in a cantilever manner, said supporting means including a disc of electrically insulating material having a plurality of apertures therein and means associated with said electrodes and extending through the apertures of said disc whereby said electrodes are secured to said disc, said first lead secured to and supporting said disc, and strap members interconnecting said first and second leads to said means associated with said electrodes.

References Cited by the Examiner UNITED STATES PATENTS 2,390,884 12/1945 Jansky 3l3260 X 2,862,135 11/1958 Payne 3l3260 3,179,837 4/1965 Johnson 313260 JAMES D. KILLAM, Acting Primary Examiner.

DAVID J. GALVIN, Examiner.

L. ZALMAN, Assistant Examiner. 

1. AN ELECTRON DISCHARGE DEVICE COMPRISING AN EVACUATED ENVELOPE, A PLURALITY OF UNITARY LEADS DISPOSED IN A REGULAR ARRAY, EACH OF SAID LEADS EXTENDING THROUGH AND BEING SUPPORTED BY SAID ENVELOPE, AN ELECTRICALLY INSULATING DISC DISPOSED WITHIN SAID ENVELOPE AND A PLURALITY OF ELECTRODES HAVING A FIRST AND SECOND END PORTION, SAID ELECTRODES BEING SUPPORTED IN A SPACED RELATIONSHIP UPON SAID DISC, SAID FIRST END PORTION BEING SUPPORTED ON SAID 